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Zeiss sf regular guy review (1 Viewer)
- Thread starter Weck
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Gijs van Ginkel
Well-known member
Ed, post 57
Attempts to clarify things is never offense, so do not worry, I sleep well. The term "brightness" obviously is a matter of definition and language. When you consult different textbooks, you will see that in quite a few "brightness" in the sense of light current/lumens is not the only way to understand the term brightness.
I will try to simplify it as much as possible:
Suppose our eye receives a photo current of 1000 photons of violet light per square centimeter and also of 1000 photons of yellow light per square centimeter (I know that you have to define the wavelenght with much more precision, but let us not look at that for a moment). In that case our eye-brain system interprets the yellow signal as brighter than the violet signal, that is what a number of textbooks say when they make a definition of brightness. Others tell us: no brightness is fully determined by the photonflux, so 10000 photons per square centimeter is brighter then 1000 photons per square centimeter regardless of the color and that is their definition of brightness.
Gijs
Attempts to clarify things is never offense, so do not worry, I sleep well. The term "brightness" obviously is a matter of definition and language. When you consult different textbooks, you will see that in quite a few "brightness" in the sense of light current/lumens is not the only way to understand the term brightness.
I will try to simplify it as much as possible:
Suppose our eye receives a photo current of 1000 photons of violet light per square centimeter and also of 1000 photons of yellow light per square centimeter (I know that you have to define the wavelenght with much more precision, but let us not look at that for a moment). In that case our eye-brain system interprets the yellow signal as brighter than the violet signal, that is what a number of textbooks say when they make a definition of brightness. Others tell us: no brightness is fully determined by the photonflux, so 10000 photons per square centimeter is brighter then 1000 photons per square centimeter regardless of the color and that is their definition of brightness.
Gijs
I'd better add a bit more detail. I guess most of the regulars here will know that the eye isn't as sensitive to the blue and red parts of the spectrum as the green and yellow but have you ever stopped to think when you look at a colourful flowerbed why the blue and red flower look brighter than the foliage or sometimes even the yellow or white flowers? Why is it that red and more recently blue LEDs are employed in instrument displays, or why stage lighting is often any colour other than white? It's been known since the nineteenth century that saturated blues and red appear brighter than greens and yellows of equal luminance. Its called the Helmholtz-Kohlrausch effect and widely utilised in many industries.
http://en.wikipedia.org/wiki/Helmholtz–Kohlrausch_effect
I've seen a scientific paper on-line that mapped specific wavelengths to brightness perception. Unfortunately I can't find it again, but one thing I noted was that the peak effect in the blue was actually shorter than the peak sensitivity for the S-cones in the retina, and like-wise, the red peak was longer than the L-cone peak. Areas of binocular transmission curve which are highly variable in the the published data I've seen, for even well respected binoculars. I've found no concrete evidence that differences in the transmission in the blue and red contribute to how we report the brightness of a binocular. For myself I frequently notice differences in what I call 'colour vibrancy' between models which seems to be the Helmholtz-Kohlrausch effect. I try to restrict 'brightness' comments to low light situations, but probably the distinction is a bit hazy.
It should be noted that those with red-green colour blindness don't see the Helmholtz-Kohrausch effect.
David
http://en.wikipedia.org/wiki/Helmholtz–Kohlrausch_effect
I've seen a scientific paper on-line that mapped specific wavelengths to brightness perception. Unfortunately I can't find it again, but one thing I noted was that the peak effect in the blue was actually shorter than the peak sensitivity for the S-cones in the retina, and like-wise, the red peak was longer than the L-cone peak. Areas of binocular transmission curve which are highly variable in the the published data I've seen, for even well respected binoculars. I've found no concrete evidence that differences in the transmission in the blue and red contribute to how we report the brightness of a binocular. For myself I frequently notice differences in what I call 'colour vibrancy' between models which seems to be the Helmholtz-Kohlrausch effect. I try to restrict 'brightness' comments to low light situations, but probably the distinction is a bit hazy.
It should be noted that those with red-green colour blindness don't see the Helmholtz-Kohrausch effect.
David
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Gijs van Ginkel
Well-known member
David,
Your post 63 illustrates very well what I tried to say with regard to brightness, thank you.
We can take another example form the world of painters and photography: when you are able to visit the Vincent van Gogh museum in Amsterdam (I can advise it, skip a new binocular and go there instead), one can see at least two paintings that illustrate very well how painters use brightness:
-1- the painting : "the potato eaters" is composed of lots of dark blue and dark green colors, not bright at all, but very beautiful.
-2- not far away from this painting one finds : "the sunflowers". They explode so to speak into your eyes and you want to use sunglasses because of the vibrant and brilliant (bright) yellow color.
Gijs
Your post 63 illustrates very well what I tried to say with regard to brightness, thank you.
We can take another example form the world of painters and photography: when you are able to visit the Vincent van Gogh museum in Amsterdam (I can advise it, skip a new binocular and go there instead), one can see at least two paintings that illustrate very well how painters use brightness:
-1- the painting : "the potato eaters" is composed of lots of dark blue and dark green colors, not bright at all, but very beautiful.
-2- not far away from this painting one finds : "the sunflowers". They explode so to speak into your eyes and you want to use sunglasses because of the vibrant and brilliant (bright) yellow color.
Gijs
Gijs,
I've only seen the version of the Sunflowers in the National Gallery in London, and, though beautiful as it is, it doesn't seem nearly as 'bright' as some of the renaissance paintings in the adjacent galleries with their use of ultramarine and crimson. I thought one of the Breugels would offer a better example but this modern tribute (??) does quite well from a distance where the blues and reds stand out more strongly to my eyes than the yellows, greens and whites.
http://www.dickjewell.com/Breugel.html
David
I've only seen the version of the Sunflowers in the National Gallery in London, and, though beautiful as it is, it doesn't seem nearly as 'bright' as some of the renaissance paintings in the adjacent galleries with their use of ultramarine and crimson. I thought one of the Breugels would offer a better example but this modern tribute (??) does quite well from a distance where the blues and reds stand out more strongly to my eyes than the yellows, greens and whites.
http://www.dickjewell.com/Breugel.html
David
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edwincjones
Well-known member
BruceH
Avatar: Harris Hawk
Here are links to what I believe are the example paintings being referenced ...
http://www.vangoghmuseum.nl/en/collection/s0005V1962
http://www.vangoghmuseum.nl/en/collection/s0031V1962
Van Gogh is thought to have had vision problems some think were caused by the lead based paints he used.
http://blog.vangoghgallery.com/index.php/2008/06/06/van-goghs-vision/
There are many other theories about it listed in his wiki biography.
See also - http://www.esrf.eu/news/general/van-gogh/van-gogh-paintings-lose-shine - it seems what we see now as 'bright yellow' in his paintings is a shadow of what once was, so brightness even in the context of his pictures is just as problematic
Barrie
Gijs van Ginkel
Well-known member
BruceH, post 67,
Yes these are the paintings I referred to. You can see for yourself how bright the sunflowers look in comparison with the potato eaters.
Gijs
Yes these are the paintings I referred to. You can see for yourself how bright the sunflowers look in comparison with the potato eaters.
Gijs
bh46118
Well-known member
I'm no Einstein:king:, but I know for sure that the SV has an extraordinarily bright image along with rich, dense color saturation. I can't help but wonder if some of the reason is the 93% transmission in the blue spectrum ? Bright usually = washed out, at least considerably more than I see in the SV. The two SE's I had were very bright, but I felt contrast suffered.
Torview
Totally respect your opinion on this, don't let my joshing make you think I don't. Nor does the joshing mean I am trying to talk down the qualities of the EL SV.
I don't think Swaros claims are quite matched by SV though because their phrase 'razor-sharp display up to the image periphery' suggests that the SV has the same sharpness at the edge as the middle. And while it is pretty sharp at the edge it isn't as sharp there as in the middle. The pre-prod SFs were not as sharp at the edge as the centre either and I will be looking out for this when I test. But for me edge sharpness is just one factor amongst many to consider.
Lee
bh it would be interesting to hear what you think of the view through an Ultravid 8x42 which to my eyes has the most saturated colours of the alphas.
Lee
Torview
Well-known member
Hi Lee, I'm just enjoying the chat on here too, and give my point of view with no expectation that others will concur, but that's what I like about this forum.
I really like the SV & SF both, but I don't lust after either.
I did get to try the Hdx Leica 7x42 today and I'm smitten, I haven't worked out why yet but this will be my Alpha roof purchase. Simply stunning to me.
I really like the SV & SF both, but I don't lust after either.
I did get to try the Hdx Leica 7x42 today and I'm smitten, I haven't worked out why yet but this will be my Alpha roof purchase. Simply stunning to me.
bh46118
Well-known member
I bet I would like it. I thought the Kowa Genesis also had nice color saturation. I'm just kind of intrigued with the high blue spectrum transmission, could it be part of the "secret sauce" ?
Gijs,
When I was a youngster we stored the potatoes we had grown in our basement in a cool, damp, gloomy fruit cellar that looked like the hovel the potato eaters were dining in but we never ate there! We had a home over it.
Bob
I can understand that and if a fairy godmother was buying bins for me over and above my Zeiss stable then Ultravid 7x42 would be one I would choose (the other would be EL SV 8x32).
Lee
Gijs has measure that at 450nm HT passes 10% more light than Ultravid and I think Uvid has more intense colours (but to me these are not life-like). Go figure.
Lee
Hermann
Well-known member
GLOBETROTTER
Well-known member
HI To everyone.
I am new in this forum but i was using quality optics all my life. Carl zeiss jena, zeiss 10x40 bgat, zeiss 10x56 night owls, leica ultravid 8x42 BL and SV 10X42.
Today i got a Zeiss SF 8X42 and fist thing i can say as expected the SF is brighter than my Ultravid 8x42 BL but the Leicas are sharper by far.......and the focus is much more accuracy, you really know when the Leicas are in perfect focus, but with the Zeiss you have to play a little bit but It has always been like with zeiss.
Color saturation is lower in the zeiss but it looks more realistic, black are blackest on leica and as a result gives the appearance of being much more contrasted, so i will need more time to check it.
And YES THEY ARE VERY VERY TRANSPARENT !!!!! like No glass influence in the view.......but i need to check it not agains my ultravid the test is again my SWAROS SV.
First impressions i will post a non professional review during next days.
Best regards fron Spain.
I am new in this forum but i was using quality optics all my life. Carl zeiss jena, zeiss 10x40 bgat, zeiss 10x56 night owls, leica ultravid 8x42 BL and SV 10X42.
Today i got a Zeiss SF 8X42 and fist thing i can say as expected the SF is brighter than my Ultravid 8x42 BL but the Leicas are sharper by far.......and the focus is much more accuracy, you really know when the Leicas are in perfect focus, but with the Zeiss you have to play a little bit but It has always been like with zeiss.
Color saturation is lower in the zeiss but it looks more realistic, black are blackest on leica and as a result gives the appearance of being much more contrasted, so i will need more time to check it.
And YES THEY ARE VERY VERY TRANSPARENT !!!!! like No glass influence in the view.......but i need to check it not agains my ultravid the test is again my SWAROS SV.
First impressions i will post a non professional review during next days.
Best regards fron Spain.
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